Presentation on theme: "Weathering and Erosion. Weathering The breakdown do the materials of Earth’s crust into smaller pieces."— Presentation transcript:
Weathering and Erosion
Weathering The breakdown do the materials of Earth’s crust into smaller pieces.
Physical Weathering Process by which rocks are broken down into smaller pieces by external conditions. Types of Physical weathering –Frost heaving and Frost wedging –Plant roots –Friction and impact –Burrowing of animals –Temperature changes
Friction and Repeated Impact
Burrowing of Animals
Chemical Weathering The process that breaks down rock through chemical changes. The agents of chemical weathering –Water –Oxygen –Carbon dioxide –Living organisms –Acid rain
Water Water weathers rock by dissolving it
Oxygen Iron combines with oxygen in the presence of water in a processes called oxidation The product of oxidation is rust
Carbon Dioxide CO 2 dissolves in rain water and creates carbonic acid Carbonic acid easily weathers limestone and marble
Living Organisms Lichens that grow on rocks produce weak acids that chemically weather rock
Acid Rain Compounds from burning coal, oil and gas react chemically with water forming acids. Acid rain causes very rapid chemical weathering
Warm-up What are the 2 types of weathering? Give examples for each. Gu4ys
Karst Topography A type of landscape in rainy regions where there is limestone near the surface, characterized by caves, sinkholes, and disappearing streams. Created by chemical weathering of limestone
Features of Karst: Sinkholes
Features of Karst: Caves
Features of Karst: Disappearing Streams
Erosion The process by which water, ice, wind or gravity moves fragments of rock and soil.
Water Erosion Rivers, streams, and runoff
Ice Erosion Glaciers
Mass Movements Landslides, mudslides, slump and creep landslide clip.mpeg
Erosion Demo b.htm
What is soil? Made of weathered rocks Soil composed of: –Sand –Silt –Clay What else is in soil? –Hint: the top dark layer?
Soil Erosion-Warm up Why do humans need soil? How does human activity affect our soil? How can we reduce soil erosion?